Tie and clamp means for concrete forms



NOV. 8, 1938. J J HILLS 2,135,509

TIE AND CLAMP MEANS FOR CONCRETE FORMS Filed July 27, 1936 INVENTOR i .foskp/zJTHJ/ls a /4 W ATTORNEYS Patented Nov. 8, 1938 PATENT OFFICE TIE AND CLAIVIP MEANS FOR CONCRETE FORMS Joseph J. Hills, Birmingham, Ala.

Application July 27, 1936, Serial No. 92,827

6 Claims.

My invention relates to tie bars for clamping and securing in position concrete forms.

Present standard specifications require that the forms for pouring concrete walls, etc., shall have the sides of the forms clamped together by tie members which are left embedded in the concrete with their ends spaced a specified distance, generally 2", from the exposed surface of the concrete wall and covered by the application of concrete plugs or other protective media.

My improved form clamp comprises a rolled tie bar, the ends of which are shaped to interlock with separable screw tension members that are adapted to wring off the ends of the bars which theyv engage when being withdrawn from the concrete. This leaves sockets into which the tie bars do not project, and which therefore can be readily and completely filled with concrete to protect the bar ends from exposure.

My invention is particularly concerned with the tie bar stock itself which is so designed that it can be produced in any width required and supplied on the job in convenient mill lengths. From this stock, selected as to width according to the tension strength required for their particular use, the individual tie bars are cutas needed, their length being controlled by the thickness of the concrete to be poured.

I have conceived that rolled bar stock can be 39 successfully used for my improved tie bars merely by, deforming it on predetermined centers to provide a series of bosses or shoulders, the end ones of which are adapted to be interlocked in a complemental slot across the inner end of the clamp members and to be wrung off by a shearing action when such end members are twisted out of the concrete.

My invention also contemplates designing these separable end tension or clamp members with a 40 case hardened end socket adapted to fit snugly about a shouldered end of the tie bars when interlocked with a side wise motion, which permits the same end tension members to be used with varying widths of tie bars selected according to the stresses they must withstand. By rolling the tie elements as bar stock with slightly raised shoulders spaced, say, on one: inch centers, the net weight of my tie bar stock need be increased only about 2%. over similar fiat bar stock to provide the suitable shoulders for interlocking sections thereof with the tension clamp members and such rolled shouldered bars can be cut on" readily on the job to the required tie bar lengths without a loss exceeding 1 per tie bar, which includes both the waste in the cutting of the bar stock to length and the wastein the wringing ofi of the ends of the tie bar incident to the removal of the end tension members that engaged it in the concrete.

My invention further comprises the novel details of. construction and arrangements of parts which, in their preferred embodiment only, are illustrated in the accompanying drawing which forms a part of this specification, and in which Fig. 1 is a cross sectional view taken through a concrete form showing my improved type of clamp means in position to brace the form sides;

Fig. 2 is a similar view showing the concrete poured and set in the form with one end of the end clamp members removed so as to show the manner in which it wrings off the end of the tie bar even with the inner end of the socket which it leaves in the concrete;

Fig. 3 is a fragmental view of the inner socketed end of a clamp member;

Fig. 4 is an inner end view of Fig. 3;

Figs. 5 and 6 show respectively edge and plan views of the rolled tie bar stock, broken away; and

Fig. '7 shows in transverse cross section three different widths of the same design of tie bar stock, all adapted for use with the clamp member shown in Fig. 4.

Similar reference numerals refer to similar parts throughout the drawing.

In the embodiment of my invention illustrated, I show a typical form set for the pouring of concrete, comprising lagging Ill, studs 1 I and double Whalers [2. The clamp elements to hold the form walls properly tied must be capable of resisting very high outward pressures, these being definitely calculated for each foot of depth of the concrete wall, abutment, footing or the like which is being poured. The means to clamp the form sides together comprises a tie bar l3, preferably of rolled stock deformed at suitably spaced intervals to provide enlargements or shoulders M, which shoulders preferably lie in opposed pairs on opposite sides of the otherwise flat bar stock and they extend across the full width of such side faces.

A very slight shoulder or offset only is sufficient for my purposes. I have successfully used fiat bar stock l3 which is thick with its shoulders raised j g" and tapered slightly outwardly to easily clear the forming rolls. These dimensions are only illustrative and should not be understood as limiting my invention to any particular shape or size of tie bar stock. Slight shoulders of this kind raised on both sides of the bar stock, while ample for the clamp member to engage, do not increase the Weight of metal per unit of length of bar stock more than 2%.

I provide end clamp members l5 adapted to interlock with the tie bar and apply the requisite clamping action to hold the sides of the form in position. This end clamp or tension member is formed of cylindrical stock, preferably steel, having its inner end slightly tapered and provided with a cross cut slot forming at its inner end a recess 16, which conforms to and is adapted to receive the shouldered portion I4 of the tie bar stock, and a slot H, which opens through the inner end of the clamp member and is shaped to snugly receive the unshouldered portion l3 of the tie bar. The end corners l8 on each side of the slot I! constitute shearing edges which are adapted to be ground down, as occasion requires, to sharpen them. The clamp element preferably has its slotted end case hardened so that these shearing edges will stand up under the contemplated service.

These clamp members are intended to be inserted through the double Whalers and between the studs and through the lagging and at their inner ends project into the form space the standard distance which the tie bar shall be spaced from the surfaceof the concrete wall, usually 2".

The tie bars are cut to suitable lengths from bar stock so that their shouldered ends can be engaged with the clamp members and the form braced in position to receive the concrete by the application of tail nuts 19, which are screwed on the threaded outer ends of the clamp members and against washers 20 on the double Whalers. The extreme outer end of each clamp member I5 is formed with a cross bored hole 2|.

After the concrete 22 has been poured in the forms it is allowed to set around both the tie bars [3 and the end clamp members l5 which respectively engage them. When the concrete has sufficiently set for the removal of the forms, the tail nuts l9 are not run ofi, but rods or bars are fitted through the end holes 2| and the clamp members l5 are turned thereby while under tension and in either direction about their long axis to break their bond with the concrete and also to wring ofi, by a shearing action of their cutting edges l8, the shouldered ends of the tie bar stock engaged in their slotted ends. The clamp members are then removed, and the tie bar stock is left flush with the inner ends of the sockets that remain; These sockets are slightly tapered inwardly and will readily receive plugs to fill them and protect the ends of metal tie bars from exposure.

Variations in tensile strength required for tie bars can readily be. had from rolled tie bar stock that varies only in width. Such variations in tie bar stock are illustrated in Fig. 7, and all of these tie bars, l3, 13a, l3b, are adapted for use with the same standard clamp members l5 shown in Figs. 3 and 4. Thus, the same clamp member will work with any tie bar the width of which does not substantially exceed the length of the shearing corner edges [8 on the clamp.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications, without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims.

What I claim is:

1. A concrete tie and clamp means, comprising in combination a tie bar consisting of a section of bar stock rolled with spaced enlargements, and clamp members having slotted ends adapted to interlock with end enlargements on an interposed tie bar and provided with shearing edges adapted by rotation of the clamp members to cut off such ends of the tie bar with which they were respectively interlocked.

2. A concrete form tie and clamp means, comprising tension members having form engaging elements adjustably mounted thereon, a tie bar adapted to be interposed between said tension members with its ends spaced from the form, end shoulders on the tie bar, there being a cross slot at the inner end of each tension member adapted to permit them to be interlocked with the shouldered tie bar ends by a relative sidewise movement, and end shearing edges on said tension members adapted to shear ofi the interposed tie bar ends.

3. A concrete form tie and clamp means according to claim 2, in which the clamp tension members are round bars which at their outer ends are threaded to receive clamp nuts and formed with a tool grip to receive a tool adapted to rotate the clamp bar about its long axis.

4. In combination, a fiat bar cut to length from stock, rolled to provide opposed pairs of transverse tapered shoulders producing a relatively slight enlargement in the thickness of the baron equi-distant, closely spaced centers, and clamp means comprising rotatable tension members transversely slotted at their inner ends to receive and interlock with the end shoulders of tie bars.

5. In a clamp and tie for concrete forms, the combination with cylindrical clamps each having a transverse slot of the T-head type across its inner end, of a tie bar selective as to Width rolled from stock having a cross section adapted to pass freely through the clamp slot transversely of the clamp and formed with shoulders adapted to interlock the bar against endwise displacement from the clamp slot.

6. A clamp and tie for concrete forms according to claim 5, in which the clamp members have their inner slotted ends cylindrical and tapered whereby they are rotatable to shear the tie bar preliminary to their removal from the finished concrete in the forms.

I JOSEPH J. HILLS. 

